Machine for making printing plates



Dec. 1924. 1,518,904

J. 5. DUNCAN MACHINE FOR MAKING PRINTING PLATES Filed Sept. 11, 1922 3Sheets-Sheet J Dec. 1924- 1,518,904

J. 5. DUNCAN MACHINE FOR MAKING PRINTING PLATES F iled Sept. 11, 1922 3Sheets-Sheet 2 J.S,DUNCAN MACHINE FOR MAKING PRINTING PLATES Filed bept.11, 1922 3 Sheets-Sheet 5 flxL F L Patented a. 9,1924.

UNITED STATES 1,518,904 PATENT OFFICE.

JOSEPH S DUNCAN, OF CHICAGO, ILLINOIS, ASSIGNOB '10 ADDRESSOGRAPHCOMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

MACHINE FOR MAKING PRINTING PLATES.

Application filed September 11, 1922. Serial 587,278.

useful Improvements in Machines for Making Printing Plates, of which thefollowing is a specification.

This invention relates to machines of the general type disclosed in myPatents No.

' 921,600 patented May 11, 1909, and No.

955,116 patented April 12, 1910, which are employed for pressing orstamping printing characters in relief on printing plates. And theprincipal object of the present invention is to provide'a machine with aplurality of keys arranged in a keyboard for operation like atypewriting machine at a comparatively high rate of speed and withoutrequiring any special mechanical skill or instruction.

' A further object of the invention is to provide a keyboard machine formaking printing devices of the kind referred to in my prior patentswhich embodies a rotating die head carrying a plurality of punches anddies in pairs arranged to make an impression upon an interposed plateand adapted to be operated entirely from the keyboard, there beinggroups of automatic and safety devices embodied in the machine to enableit to be operated rapidly and by the comparatively simple manipulationof the keys similar to an ordinary typewriting machine.

A further object of the invention is to provide the machine with safetydevices whereby one key only can be operated at a time and whereby thecomplete cycle of operation must he proceeded with upon the depressionof one key before any other key can 'be depressed, except in specialcases, and also to provide manually operated means whereby a key may berestored to normal position without the necessity of completing thecycle of operation of the other parts of the machine.

Other objects of the invention are to pro vide a normally rotating diehead having means for accurately stopping the head and for locking thehead to make an impression from a selected die and punch; toautomatically release the head as soon as the impression is made so thatits rotation may be resumed; to quickly restore the depressed key tonormal position when its punch and die have operated; to arrange theseveral groups of mechanism so that they will operate in proper sequenceand quickly to enable rapid operation of the machine and to providemeans for insuring proper operation of the machine and to preventirregular operation or jamming of the parts.

And the invention also has for a primary ob ect the provision of akeyboard machine adapted for rapid operation for making printing plateswhich can be sold to the trade generally for use as an office applianceto be operated by young people having no mechanical experience and whichwill require very little instruction beyond mastering the keyboard whichmay conform to the standard keyboard in use on typewriting machines. Inthe accompanying drawings illustrating a selected embodiment of theinvention and which I have found satisfactory in practical use Fig. 1 isa front elevation of the machine, partly in section;

Figs. 2, 3 and 4. are sectional views on ghe lilnes 2-2, 3-3 and 44respectively of Figs. 2 and 2 are detail views partly in section;

Fig. 5 is an enlarged view of the die head locking devices;

Fig. 6 is an enlarged elevation of the key locking and restoringdevices;

Fig. 6 is a detail view;

Fig. 7 is a side elevation of the manually operated. key restoringmeans.

Referring to the drawings the main frame 10 is mounted on a suitablebase 11 which may be supported on legs 12 or in any other suitablemanner. A die head 13 is mounted in the frame to rotate about a verticalaxis. A pulley 14.- (Fig. 4:) communicates power from any suitablesource to a main driving shaft 15 which is provided with a bevel gear 16meshing with a bevel gear 17 on a vertical shaft 18 which drives the diehead through a suitable friction device 19. The die head carries aplurality of dies 20 and punches 21 arranged in complementary pairs andmovably mounted therein and adapted to be operated to make an impression(stamp a die character in relief) on an interposed plate which is causedto travel by step by step or other movement along atable 22 and iscarried by a carriage which it is not considered necessary to illustratein this application. A punch stock 23 is slidably arranged in themainframe to enga e a punch 21 and a die stock 24 is forme on the dieshuttle arm 25 to engage the cor-1 res onding die. This arm is pivotedat 26 an it sup orts the shuttle 27 which is adapted we ide back andforth thereon and is engaged in 0 erative position by an'anvil 28carried by t e head 29 of a rock lever 30 which is also ivoted at 26.The head 29- is operated by t 1e toggle 31 which is pivoted to the mainframe at 31 and is operated by the shaft 32 (Fig. 4') which is in turnoperated by the pitman rod 33 and the ec-.

centric 34 on the main driving shaft 15, or in any other suitablemanner. The toggle rotates continuously except during the impressionmovement of a pair of punches and dies, and the toggle preferablyoperates continuously also. The shuttle 27 1s provided with a recess 35which is disposed opposite the anvil 28 under normal conditions toprevent the anvil from depressing the die stock to o erate a die, butwhen the die shuttle has. een projected to the right in Fig. 1, to bringthe seat 36 thereof in alignment with the anvil 28 the shuttle will bedepressed, the arm 25 will be rocked on its pivot and the die stock 24will operate a die, the rotation of the head having by that time beenstopped and the head locked against movement while the punch and die arebeing operated. An arm 37 on the shuttle arm 25 is provided with a stopscrew 38 adapted to be adjusted to en age the main frame or other fixedpart to Timit the upward movement of the die shuttle. A

spring 39 is connected to the arm 37 and to the main frame and tends tohold the die shuttle in elevated position, as shown.

A- punch shuttle 43 is slidably mounted on the head 44 carried by thelever 45 which is pivoted at 46 on the main frame and is operated bycrank pin 47 and connecting rod 48 on the main driving shaft 15. Thehead 44 is carried by a rod 49 slidably mounted in the lever 45 andnormally held in raised position by the spring 50. The lever 45constantly operates like the toggle 31 and the die head, and the punchshuttle has a recess 51 and corresponding with the recess 35 in the dieshuttle so that the punch stock 23 will be engaged only when the punchshuttle is moved to the right in Fig. 1 in alignment with the punchstock.

A link 53 connected to the die shuttle and v a link 54 connected to thepunch shuttle are pivotally connected to a rock lever 55 which ispivoted at 56 on the main frame. A sprlng 57 is connected to one arm 58of the rock lever 55 and to the main frame to hold the shuttles normallyout of operative position, as shown in Fig. 1. Y

The die head is normally rotating, as

stated, and means are provided for quickly and accurately sto pin thehead and for preventing any re oun A hollow shaft 59, Figs. 1,3, 9, isrigidly secured to the head and rotates therewith.

An arm 60, Fig. 2, rigid on the shaft 59 has a striker 61 arran ed abovethe circular series of stops 62 slidmgly mounted in the ring '63 whichis secured to the base 11 by bolts 64 or other suitable means, Fig. 1.The stops are each connected by spring 65 with a ring 66 which issupported in spaced relation to the ring 63 by rods 67. The stops arelifted against the tension "of their springs by corresponding key bars68 (Fig.

4) which are pivoted at 69 on posts 7 O and carry keys or finger pieces71 on their outer ends which are preferably arranged in substantialaccordance with a standard key board. When a key is depressed its keybar is rocked and its stop is lifted into the path of the striker 61 andsince the arm 60 is rigid with the shaft 59 and the latter is rigid withthe die head it follows that the die head will come to rest when thestriker en 'ages the lifted stop.

To prevent any rebound of the head when the striker engages a stop "apawl 72 (Fig. 2) is pivoted at 73 on the extension 74 of the striker arm60 and a spring 75 pulls the pawl inward-1y in position to engage thatside of the lifted stop opposite to the striker 6-1. The pawl has aninclined face 77 which will first engage the lifted stop and cause thepawl to swing outward against the tension of spring 75 but the parts areso proportioned that when the striker engages one side of a lifted stopthe inclined face of the pawl will have passed by the stop so that thelip 76 of the pawl may be engaged with the stop under the action of thespring 7 5. Since the action of the pawl is practically coincident withthe engagement of the striker with a lifted stop and since theengagement of the pawl with the stop will prevent any rebound of the diehead it will be understood that when the die head is brought to a stopit is a dead stop without any rebound o-r vibration, and this is highlydesrable for accurate work.

The pivot 73 for the pawl is preferably located beyond the circle of thestops to facilitate the operation of the pawl. It is desirable to havethe shuttles and the punchand die corresponding with the depressed keyoperate immediately when the die head is stopped by depressing a key,and quickly so that the machine may be operated at considerable speed.The lower free end of the rock lever 55 is loosely connected with onearm of the bell crank lever 78, Fig. 1, which is pivoted at 79 on abracket 80 sesured to the base 11 and carries at the end of its otherarm a pivoted bearing 81 for a rod 82 which. extends through the plug 83in the lower end of the hollow shaft 59 and projects upwardly even withthe stop arm 60. The rod 82-carries a collar 84 between the pivot 81 onthe lever 78 and the arm 85 fastened to said lever so that the rodnormally holds the latch in position to en gage the upper end of the rod82-with its free end projecting rt way across the circle of the stopsant slightly in advance of the striker. The face of the striker israised at 61 to permit the outer end of the latch to seat therein whenthe latch is swung on its pivot by engagin with a lifted stop to releasethe rod 82. his seating of the end of the latch in the recess of thestriker permits the striker to engage the lifted sto at the same timethat the rod 82' is release by the swinging of the latch. And when thelatch 86 is withdrawn front engagement with the rod 82 the spring 57, Fi1, is enabled to rock the bell crank lever 78 and the shifting lever toshift the shuttles into operative position so that the next movement ofthe toggle 31 and the lever 45 will cause the die and punchcorresponding with the key that has been depressed to cooperate andproduce a type character on the interposed plate.

' To return the shuttles to their normal inoperative position and alsoto return the rod 82 to position for engagement with the latch 86, Iprovide a lever 93 (Fig. 1) which is pivoted at 94 on the main frame andcarries a kicker 95 pivoted to its lower end 96. This kicker rojectsbetween the springs 97 and 98 on t e guide 99 carried b the lever 93 andconsequently it has a yiel ing movement on'its pivot in both directions.The forward free end of the kicker is wedge-shaped or tapered and itnormally lies beneath the die shuttle but is arranged to enter a notch102 in the die shuttle when the latter is lowered in its operatingmovement. A link 103 is connected with the toggle and with the lever 93so that the kicker is continuously operating with the toggle. It will berecalled that when the shuttle die moves to operative po sition itslides to the right, Fig. 1, and moves downward, and during thismovement the yieldingly held kicker enters the slot 102 so thatimmediately after the impression operation and when the toggle flexes,the kicker is caused to pushthe die shuttle back to its normal positlonand in so doing the punch shuttle is returned to its normal position inthese arms by means of and the rod 82 is lowered for engagement with thelatch.

It is desirable to prevent o eration of a second key before the competion of the cycle of operation produced by depressing one key and it islikewise desirable to return a depressed key to normal position asquickly as possible after it has performed its function. To accomplishthese results I provide a pair of arms 104 and 105 which project forwardalongside the keyboard, Fig. 2; and a key locking bar 106 is pivotallymounted intles 107 and 108. This key-bar has a ownwardly inclined flangeor blade 116 and an upwardly inclined flange or blade 117 (Fig. 6). Alug 109 on the flange 116 is arranged to engage a pin 110 on the arm 104to limit the movement of the key bar under the influence of spring 111which is attached at 112 to the arm and at 112 to the flange 116 belowthe intle 107. Each key bar is provided Wit 1 a downwardly projectingleg 113 which has an inclined lower end 114 turned over to provide asmooth footing for engagement with the flange 116 of the locking bar.When a key is depressed to raise a stop the locking bar is rotatedclockwise by engagement of the leg 113 with the flange 116 and as thedownward movement of the leg continues the edge 116 of the flange 116engages the shoulder 119 on the leg. At the same time, the upper flange117 of the key bar swings into engagement with the shoulders 118 of allthe other key bars. The construction is such that the shoulder of thekey bar which is depressed will clear the flange 117 before the latterengages therewith, so that at the completion of the depressing movementof a key the depressed key will be locked in lowered position byengagement of the flange 116 of the locking bar with the leg 113 of thedepressed key bar, and all of the other key bars will be locked innormal position by engagement of the flange 117 of the locking bar withthe shoulders of the other key bars.

To release the key bars from the locking bar which holds the depressedkey and all the other keys in locked position I provide a release bar120, Figs. 4, 6, which is carried below the key bars by link 121 and abell crank 122 pivoted at 122' on a fixed part of the machine. A pawl123 1s pivoted to the release bar and a spring 123' normally holds thepawl in approximately the position shown in Figs. 4 and 6 beneath theflange 116 of the locking bar and in engagement with the lower edge 116thereof. The die shuttle arm 25 is provided with an extension 25'(Fig. 1) WlllCh is connected by a link 125 with an arm 126 of the bellcrank 122 (Fig. 4). When the die shuttle arm is lowered in the operationof making an impression the link 125 is also lowered to swing the bellcrank 122 and thereb thrust the release bar 120 to the right in igs. 4and 6 until the edge 127 of the pawl 123 engages the lower edge 116 ofthe flange 116 of the looking bar. Then when the die shuttle arm risesafter making the impression the release bar 120 is thrust to the left inFigs. 4 and 6 and the pawl 123 rocksthe 100 in bar until it is releasedfrom the le 113 o the depressed key, and at or about t e same time t eawl disengages itself from said flan e. T on the spring 111 returns thekey lockmg bar to normal position, releasing the keys which were notdepressed and the spring retracts the lifted stop.

To return the depressed key to normal position I provide a key replacer128, Figs. 4 and 6, which extends transversely of the ke board below thekey bars and is provided with a pad 129 to engage the lower edge of eachkey bar. The replacer is pivoted at 130 on the arm 104 and it has ashoulder 131 to be engaged by a pawl 132 carried by the releasesbar 120and operatin simultaneously with the .pawl 123.

en the release bar moves to the right, Figs. 4 and 6, the pawl 132 israised by the spring 134 connected with the release bar 120, intoengagement with the shoulder 131 on the key replacer; and when therelease bar moves to the left, Figs. 4 and- 6, the replacer is swung onits pivot and the pad 129 engages the depressed key bar and returns itto normal position quickly. Like the pawl 123, the pawl 132automatically disengages from its shoulder after the operation justdescribed and the parts assume their normal position as shown in Figs. 4and 6. It may happen that the power is shut off or the machine isotherwise brought to a complete'rest with a key depressed, or

for any reason, it may be desired to restore the key to normal positionafter being depressed without proceeding through the usual cycle ofoperation. For this purpose I pivot an angle lever 135, Fig. 7, on adownward extension 136 of the arm 105 and provided with an arm 137adapted to engage a projection 128 on the key replacer or operating thereplacer as has just been described. Another arm 138 is arranged toengage the flange 116 for operating the locking bar 106 as has also beendescribed. This arm 138 is preferably pivoted at 139 to the angle lever135 and it has a pin 140 projecting into an enlarged opening 141 in theangle lever whereby the movement of the arm relative to the lever islimited. A spring 142 is connected to a pin 143 on the arm 105 and tothe pin 140 and operates to hold the arm 138 in its upward position andalso holds the lever 135 in its normal position, as shown in Fig. 7. Theangle lever 135 is operated manually by means of the handle 144 and whenso operated, by swing ing the handle to the left, Fig. 7, the lockmglever is released from the depressed key bar andthe replacer is liftedto restore the depressed bar to normal position.

The normal resiliency of the arm 60 and the shaft 59 ma perimta slightmovement of the die hea just as the lmpression is being made and thismay result in an imperfeet impression or other undesirable result.

To prevent this and to lock the die head rigidl during the impressionoperation I provi e a lockin block 146, Figs. land 5, shdably dlSPOS oposite a series of, teeth 145 at the bottom 0 the die head and adaptedto be engaged therewith as the punch and die are being moved intooperation. The locking block is operated by the arm 25 through a link147, a bell crank lever 148v and a lever 149, the latter having asliding connection 150 at one end with the block 146. The bell crank 148and the lever 149 are pivotally connected at 151 and an arm 152 on thebell crank has a notch 153 to receive a pin 154 on the lever. A spring155 connects the free end of the lever 149 with the bell crank andnormally holds them in the position shown in Fig. 5. When the shuttle.arm 25 lowers with the operative movement of the toggle, the extension25' causes link 147 to swing the bell crank clockwise on its pivot andto cause the spring 155 to pull the lever 149 clockwise also and projectthe locking block into engagement with a pair of teeth to lock the diehead. As the to gle bends the link 147 is raised to swing 5w bell crankcounter clockwise, and the arm 152 engaging the pin 154 swings the lever149 to withdraw the locking block from engagement with the teeth andthereby release the die head. Thus the die head is positively locked inrigid position during the impression operation of the punch and die andis released from locked position when the impression has been completed.

In operation, the die head is normally rotating in a counter clockwisedirection as indicated by the arrow in Fig. 2 with the stop arm 60 andthe latch 86 traveling over the stops; the shuttles are in retractedoridle position and the toggle and the levers 30 and 45 are vibrating inunison; the latch 86 is normally engaged with the upper end of the rod82 to hold the shuttles in retracted position; and the keys are allfree. When any key is depressed its stop 62 is raised into the path ofthe latch 86 and the arm 60; the latch is first released from engagementwith the rod 82 and the spring 57 is then enabled to rock the lever 55and thereby to shift the shuttles into operative position. By this timethe striker of the arm 60 has engaged the lifted stop, the die head hasbeen brought to rest, the pawl 72 has become engaged with the liftedstop and the locking bar has shifted to hold the depressed key indepressed position and the other keys in normal position.- When thetoggle straightens and the lever 45 swings upward the shuttles are movedtoward each other to'operate the punch and die corresponding with thedepressed key for impressing a type character in an interposed plate. Asthe die shuttle moves downward the locking block 146 is thrust intoengagement with the teeth on the die head to rigidly lock the die headduring the impression operation. After the impression is made and thetog le bends and the lever 45 swings downward the locking block iswithdrawn from engagement with the die head, the release bar isprojected forward, to the right, in Figs. 4 and 6, to release the keysand to restore the depressed key to normal position. The kicker alsoshifts the shuttles i which is adapted for the production of typecharacters on printing plates from which impressions of high grade maybe printed in imitation of typewriting or otherwise. The machine issimple to operate, it requires no mechanical experience because it isautomatic in action except for the operation of the keys and they areoperated in substantially the same manner as the keys of a typewritingmachine.

I have not considered it necessary to show the carriage which feeds theplate through impression position because a carriage of this descriptionis illustrated in my former patents and forms no part of the presentinvention.

I am aware that changes in the form, proportion, construction andarrangement of parts may be made without departing from the spirit andwithout sacrificing the advantages of the invention and I reserve theright to make all such changes as fairly fall within the scope of thefollowing claims.

I claim:

1. In a machine for making printing plates, the combination of anormally rotating die head, dies movably mounted on the head, means foroperating the dies and including a shuttle, means for stopping the diehead, and means operated by the last named means for controlling theshuttle.

2. In a machine for making printing plates, the combination of anormally rotating die head, dies movably mounted on the head, means foroperating the dies and including a shuttle, means for holding saidshuttle in inoperative position, means forstopping the die head, andmeans operated by the last named means for releasing the shuttle.

3. In a machine for making printing plates, the combination of anormally rotating die head, dies movably mounted on the head,continually vibrating means for operating the dies, a shuttle forrendering the vibrating means effective, means for holding the shuttlein inoperative position, means for stopping the die head, and meansoperated by said stopping means for releasing said shuttle.

4. In a machine for making printing plates, the combination of anormally rotating die head, dies movably mounted on the head, means foroperating the dies and including a shuttle, means for holding saidshuttle in inoperative position, an arm rotating with said head, a stopadapted to be moved into the path of said arm, and means carried by saidarm for controlling said shuttle. Y

5. In a machine for making printing plates, the combination of anormally rotating die head, dies movably mounted on the head, means foroperating the dies and including a shuttle, means for holding theshuttle in inoperativeposition, a latch rotating with the die head, andmeans for causing the die head to stop and including a stop adapted tooperate said latch to release said shuttle.

6. In a machine for making printing plates, the combination of a'normally 1'0- tating die head, dies movably mounted on the head, meansfor operating the dies and including a shuttle, means for holding saidshuttle in inoperative position and including an arm rotating with thedie head, a latch rotating with the arm, and a stop adapted to be movedinto the path of said arm and latch to operate said latch and releasesaid shuttle.

7. In a machine for making printing plates, the combination of anormally rotating die head, dies movably mounted on the head, means foroperating the dies and including a shuttle, means for holding theshuttle in inoperative position and including a reciprocating rod, alatch rotating with said die head to limit the movement of said rod,means for simultaneously stopping the die head and. releasing the latch,and means for restoring the latch to operative position.

8. In a machine for making printing plates, the combination of anormally rotating die head, dies movably mounted on the head, keys andkey bars corresponding to said dies, key operated means for stoppingsaid die head, means for locking a key in operative position, means foroperating the die when the head is stopped, and means operated by thelast name means for releasing the key and the die head.

9. In a machine for making printing plates, the combination of anormally rotating die head, dies movably mounted on the head,key.operated means for stopping tating v thehead, stops for stopping thedie head,

key bars for operating the stops, means for automatically looking a keybar in operated position and the remaining keys in normal position,means for operating the dies,,. and means operated by said lastmentioned means for releasing the keys and the die head.

11. In a machine for making printing plates, the combination of anormally rotating die head, dies movably mounted on the head, aplurality of stops adapted to stop the die head, key bars for operatingthe stops, means for automatically looking a key bar in position to holdits stop 1n operated position, means for operating the dies, and meansoperated by the return stroke of the operating means for releasing thekebar.

12. n a machine for making printing plates, the combination of anormally rotating die head, dies movably mounted on the head, keyoperated means for stopping said die head, key bars for operating saidstopping means, means for locking a key bar in operated osition, meansfor operating the dies an including a shuttle lever, and means operatedby the shuttle'lever for releasing the key bar and restoring it tonormal position.

13. In a machine for making printing plates, the combination of anormally rotating die head, dies movably mounted on the head, keyoperated means for stopping the die head, key bars for operating saidstopping means, m'eans for looking a bar in operated position, means foroperating the dies and including an arm, a release bar for releasingsaid bar, and means for connecting said release bar to said arm.

14. In a machine for making printing plates, the combination of anormally rotating die head dies movably mounted on the head, keyoperated means for stopping said die head, key bars for operating saidmeans, a locking bar for locking said key bars, a release bar forreleasing said looking bar, means for operating said dies, and

means for connecting said release bar with said d1e operating means.

for operating the dies and inc uding a" shuttle, means for normallyholding the shuttle'in inoperative position, means for stopping therotating head, means for re leasing the shuttle whenthe head is stopped,and means operated by the die operating means for releasing the diehead.

16. In a machine for making printing 7 plates, the combination of anormally rotating die head, dies carried thereby, continuously operatingbut normally inefiective means for operating said dies, means forstopping the die head, means for rendering said continuously operatingmeans effective on the dies when the head is'stopped, and

means for automatically Withdrawing the stopping means after the dieshave operated. 17 In a machine for making printing plates, thecombination of a normally rotat-- ing die head, dies carried thereby,continu-v ously operating means for operating said dies, means forstopping said head, and means operated by the die operating means forlocking said head while the impression is being made.

18. In a machine for making printing plates, the combination of anormally rotating die head, dies movably mounted on said head, keyscorresponding to said dies, an arm rotating with said die head, stopscorresponding with said dies, means 0 erated by the respective keysfor-moving t e said stops into the path of said arm, means for operatingsaid dies and including a shuttle, means for locking the shuttle ininoperative position, and means rotating with said die head and adaptedto be moved by engagement with a stop for releasing said shuttle.

19. In a machine for making rinting plates, the combination of anormaliy rotating die head, dies carried thereby, means for operatingsaid dies and including a pivoted shuttle arm, means for stopping thehead, a device for locking said head, and means connected with said armfor operating said device to lock the head during the impressionoperation.

20. In a machine for making printing plates, the combination of anormally rotating die head having a series of teeth, a locking block, anoperating lever for moving 22. In a machine for making printing plates,the combination of a normally rotating die head having a plurality ofteeth, a locking device adapted to engage said teeth, and means foroperating said device comprising two levers pivotally mounted on thesame pivot, one of said levers being engaged with said device, a pin onthe other lever to engage said first mentioned lever, and a springyieldingly connecting said levers.

23. In a machine for making printing plates, the combination of aplurality of key bars, a locking bar, means operated by depressing a keybar for locking said key bar in depressed position and the other keybars in normal position, and manually operated means for releasing saidkey bars and restoring the depressed key bar to normal position. 24. Ina machine for making printing plates, the combination of a plurality ofkey bars, a locking bar for engaging and looking a key bar in depressedposition and the other key bars in normal position,

means for restoring the depressed key bar to normal position whenreleased, and manually controlled means for operating said locking barand restorer.

25. In a machine for making printing plates, the combination of aplurality of key bars, a locking bar for engaging and looking a key barin depressed position and the other key bars in normal position, meansfor restoring the depressed key bar to normal position when released,and manually controlled means comprising an arm for operating saidlocking bar to release the key bars and another arm for operating therestorer. I

JOSEPH S. DUNCAN.

